Rebounding, which is the repeated jumping on a rebounder that is similar to a small trampoline, has been found to be a highly beneficial exercise especially for middle-aged and older persons. My U.S. Pat. No. 6,652,419, which is incorporated by reference herein, describes a conditioning system that is useful in the home, which includes a hand support that is mounted in a home, across a doorway, when the apparatus is to be used, and which is removed and stored away after use. It would be desirable if a similar conditioning system were available, that was set up permanently for use in dedicated exercise establishments wherein many people exercise at the same time. It also would be desirable if such a system allowed a plurality of people each exercising on a rebounder with arm support, to easily communicate with one another to enhance the exercise experience.